Question

hi pls answer question number 9
fast with steps

Answer 1

Given:

Height of the cylindrical box h =1.5 m = 150 cm.

Diameter of the cylinder = 70 cm.

Radius of the cylinder r = (d/2) = 35 cm.

Now,

We know that Total surface area of cylinder = 2πr(r + h)

⇒ 2 * (22/7) * 35(35 + 150)

⇒ 2 * 22 * 5(185)

⇒ 2 * 22 * 925

⇒  40700 cm^2.

⇒ 4.07 m^2

Given, Cost of metal sheet per m^2 = 70.

Then, Cost of 8030 m^2 = 4.07 * 70

                                         = 284.9.

Therefore, the cost of the material used in the box = 284.9

Hope it helps!

Answer 2

Given h=1.5m, r=d÷2=35cm=0.35m
cost of metal= Rs70/sq. m
We know total surface of cylinder = 2πr(r+h)
=2×22/7×0.35 (0.35+1.5)
=4.07 sq.m
therefore cost of material used in box
=4.07×70
=Rs 284.9

Therefore cost of material used is RS 284.9